Thermally responsive unit



Nov. 30, 1948. F. R. HIGLEY THERMAL-LY RESPONSIVE UNIT Filed March 29,1944 Patented Nov. 30, 1948 THERMALLY BESPONSIVE UNIT Frank a. may,Cleveland Heights, out, assignor to Bryant Beater Company, a corporationoi Ohio Application March 29, 1944, Serial No. 528,548

1 Claim. 1

This invention relates to improvements in thermally responsive units ofthe monometallic laterally moving compensated type. The embodiment ofthe invention herein disclosed is a one piece. sheet metal stampingwhich when formed as hereinafter described, functions like a unit built.up from separate hot and cold members or legs The fact that theinvention is constructed as an integral unit the accuracy of whichdepends upon the accuracy of the dies used'in forming it rather thanupon the skill of workmen in'assembling it from separate members,-contributes materially to its success. Furthermore, since the hot andcold members are integral parts of a single stamping they cannot becomedisplaced relative to each other as may occur in an assembled device.

One of the objects of the invention, therefore, is the provision ofthermally responsive units of the character stated having greatuniformity in structure and operation.

Another object is the provision of a unit of low cost due to itsintegrality.

A further object is the provision of a unit having a high strength, massratio.

Still another object is the provision of a unit of the character statedin which the proportions may be easily modified to meet varyingoperating requirements, particularly as to the length of stroke.

Other objects and features of novelty will appear as I proceed with thedescription of those embodiments of the invention which, for thepurposes of the present application, I have illustrated in theaccompanying drawings, in which:

Fig. 1 is a plan view on an enlarged scale of a sheet metal blankrepresenting one stage of the method employed in forming my improvedunit.

Fig. 2 is a plan view of the completed unit.

Fig. 3 is an edge view of the same.

Figures 4 to 7, inclusive, are detail sectional views taken respectivelyon the lines 4l, 5-5, 6-6, and l--l of Figure 2.

In the illustrated embodiment the unit is constructed of sheet metalhaving the proper 'quali- I ties for long life under high temperatureconditions, as for example, in the control of an oven The unit embodiesaburner in a gas range. mounting portion in which two spaced members areintegrally joined along a longitudinal edge or edges, a thermallyresponsive portion in which the two members are separated and face eachother, and a motion transmitting portion in which the two members areagain joined together along the same longitudinal edge or edges. In thethermally responsive portion the twomembers constitute legs which areinsulated from each other by an air space, so that transfer of heat fromthe section in order to promote flexibility, while intermediate theirends the legs may be deformed to provide reenforcement against buckling.

Referring now to the drawings Fig. 1. shows a sheet metal strip blankwhich has been lanced or slit or otherwise longitudinally perforatedpart way of its length midway between its side edges, as indicated atH). The slit to, which is located in that portion of the blank whichcorresponds with the thermally responsive portion of the unit, dividesthat portion of the blank into two legs H and I 2. Along theintermediate portion of one or both of these legs I may providedeformations. the purpose of which is to reenforce the legs againstbuckling and yet leave their ends flat and therefore relativelyflexible. The deformations illustrated consist of ribs l3 which arepressed into the blank before or after the slit III is formed orsimultaneously with the formation of the slit. Preferably, these ribstaper from their medianpoints toward their ends, as shown particularlyin Fig. 3.

' As a result of the bending operation there is produced alongitudinally extending integral edge part I4 joining the two spacedmembers i5 and it of the mounting portion of the unit. At the oppositeend of the unit the bending operation produces a longitudinallyextending integral edge part 11, joining the two members It! and ill ofthe motion transmitting portion of the unit. In the bending operationthe members l8 and I9 are spaced apart the same distance as the membersl5 and I6. I prefer to press the members l8 and I9 together as shown inthe drawing, and when this is done the space between legs H and I2 01'the thermally responsive portion of the unit is caused to taper as shownin Fig. 3. When the bending is done the legs Ii and 12, being entirelyseparated by the slit l0, are not bent at all, but the slit opensoutwardly and the members consequently may project laterally a slightdistance beyond the edge parts I4 and I1, as shown in Fig. 2.

The blank may be of the same width through- 3 out its length, or, in themotion transmitting portion it may be reduced in width toward its freeend, as by an inclined edge 20. The consequent reduction in section ispermissible since the mounted unit serves as a cantilever and its stressdecreases toward the free end. In case the parts l8 and I9 are-pressedtogether'so as to function approximately like one thickness of metal,they may be positively connected at one or more points, as by a spotweld or welds 2|.

The unit may be mounted in various ways. As shown herein the spacedmembers II and liat the mounting end are caused to receive one leg of anangle mounting bracket 22 which projects between members l5 and I6 andthereby serves to gage their spacing. A spot weld 23 through the threethicknesses of metal flxes the unit upon the bracket. At the free end ofthe unit provision may be made for connecting it with a control, suchprovision in the illustrated case consisting merely of a perforation 24adapted to receive a suitable connection. 9

Having thus described my invention, I claim:

A monometallic thermally-responsive unit of elongated form adapted forlateral deflection, comprising a piece of sheet metal having alongitudinally extending bend providing a pair of elongated membersgenerally of strip form, disposed alongside each other in slightlyspaced facing relation, said piece being perforate along a 30 portion ofsaid bend intermediate the ends thereof. said members having integralinterconnection along said bend, longitudinally beyond each endintermediate their ends.

' FRANK R; HIGLEY.

REFERENCES crran The following references are of record in the' fileofthis patent:

UNITED STATES PATENTS Number Name Date 361,899 Smith Apr. 26, 1887873,511 Cyphers Dec. 10, 1907 914,859 Moore Mar. 9, 1909 1,193,637Inwagen Aug. 8, 1918 1,666,413 Foster Apr. 17, 1928 1,812,788 HurxthalJune 30, 1931 1,987,166 Valverde Jan. 8, 1935 1,991,495 Derby Feb. 19,1935 2,086,857 Derby July 13, 1937 2,122,325 Rumball Jan. 28, 19382,185,436 Gordon Jan. 2, 1940 2,204,781 Davis June 18, 1940 2,354,655Anderson Aug. 1, 1944 2,361,530 Burch Oct. 31, 1944 Y FOREIGN PATENTSNumber Country Date 213,596 Great Britain June 29, 1925

